Blackboard ruling device



J. 0. CLICK BLACKBOARD RULING DEVICE Nov. 25, 1958 Filed March 29, 1957INVENT OR JAMES 0. CL/GK a 4 u 7 m 2 AT L M u FIG. 2'

- ATTORNEYS nited States Patem 2,861,343 BLACKBOARI) RULING DEVICE James0. Click, Wilder, Idaho Application March 29, 1957, Serial No. 649,337

3 Claims. 01. 33-41 This invention relates to a blackboard rulingdevice. More specifically this invention relates to a device for drawinga line or lines on a blackboard or'the like, said line being parallel tothe chalk tray or other surface which supports the device. Morespecifically, this invention relates to a blackboard ruling devicecomprising a rectangular frame having a base and two verticallyextending sides at the opposite ends thereof, said sides having a bridgemember adapted to be clamped therebetween at a selected vertical height,said bridge member having thereon means to hold a conventional markinginstrument. In use, the structure is supported with its base on ahorizontal supporting surface and the marking instrument engaging avertical Writing surface. The structure is then moved along thesupporting surface whereby the marking instrument scribes a line on thewriting surface.

Attempts have been made in the past to produce satisfactory blackboardruling devices. One such attempt is shown in the United States Patent1,186,716 to Walker. One of the devices in the prior art comprises awheeled triangular figure, one side of which is perpendicular to thewheeled base. Attached to the device. and slidable along theperpendicular side thereof is a roller marking instrument which isspecially designed for use with the device.

The prior art does not show simple means by which conventional markinginstruments may be used on devices of this general nature. Also thedevices of the prior art do not provide adequate means for easilyadjusting the vertical height of the marking device.

Accordingly, it is an object of this invention to provide a blackboardruling device with novel means for holding in vertically adjustabledisposition a conventional marking means.

It is another object of this invention to produce a device for rulingthe blackboard featuring unusually simple and easy means for verticallyadjusting and accurately fixing the marking instrument.

It is yet another object of this invention to provide a blackboardruling device having a simple and sturdy structure.

This invention embodies other novel features, details of constructionand arrangement of parts of which are hereinafter set forth in thespecification and claims, and illustrated in the accompanying drawing,wherein:

Fig. 1 is an elevational view showing the device supported in ablackboard chalk tray;

Fig. 2 is a horizontal sectional view taken on line 22 of Fig. 1;

Fig. 3 is a side elevational view showing the device supported in achalk tray;

Fig. 4 is an enlarged fragmentary sectional view taken on lines 4-4 ofFig. 1.

Referring more specifically to the drawings, my invention comprises arectangular frame having a base 12 with parallel vertical upstandingsides 14 and 16 at opposite ends'thereof. A top member'18 parallel 'tobase 12 connects the two sides at their upper ends. As is best shown inFig. 4, base 12 may comprise a pair of slats 20 and 22 in parallel sideby side relation secured to the opposite sides of each of the sidemembers respectively. To provide a neat appearance the lower ends of theside members are preferably mitered. A pair of spindles 24 and 26 areconnected between the two base slats and on each of them rotates a wheel'28 and 30. The lower surface of the wheels must extend below the lowersurface of the-slat members in order that the wheels may provideantifriction means to support frame 10. The wheels may be rubber-tiredto reduce noise and assure good frictional contact with the supportingsurface, normally a cleared chalk tray'C as is shown in Fig. 1.

Spanning the two vertical side'members is the vertically adjustablebridge member 32. Bridge member 32 comprises a pair of elongated members34 and 36 in parallel side by side relation, one on either side of theframe (see Fig. 4). The elongated member 36 may comprise a pair of slats38 and similar to'base slats 20 and 22. The slats 38 and 40 of elongatedmember 36 are spaced by means of block spacers 42 at the center andadjacent the end of member 36. Connected between the slat members of'theelongated member are a pair of spindles 44 and 46 disposed parallel tothe side members. On these spindles rotate wheels 48 and 50 respectivelya portion of each of which extends outwardly beyond the slats 38 and 40to engage the blackboard or other writing surface B. The other elongatedmember 34 is a flat bar. Elongated member 34 and 36 have a pair ofaligned horizontally disposed bores 52 and 54 therethrough. The boreseach receive from the wheeled side of the elongated member a threadedmember'56 the head of which is held against rotation. The bores throughthe elongated member 34 are somewhat larger in diameter than thediameter of the threaded members so that the elongated member. 34 may beeasily moved in a direction axial to the threaded members 56. The freeend of the bolts are fitted with a compression spring 58, a washer 60,and a wing nut 62.

To the top surface of the bridge member at its center is secured a block64 having a notch 66 in the center of the upper surface thereof. Asimilar block 68 with a matching notch 70 opposes and is disposedimmediately thereabove. The upper block 68 is apertured, and extendingupwardly from the lower block 64 are a pair of threaded studs 72 adaptedto pass through said apertures. Wing nuts 74 are provided for the upperfree ends of the threaded studs. Thus, a conventional writing instrumentI, namely, a pencil, pen, or piece of chalk may be fitted in the opposednotches 66 and 70 of the members 64 and 68 and the wing nuts 74tightened to clamp them together between said members. The clamp members64 and 68 are adapted for use with a marking instrument of the fluiddispensing type. One of such instruments is presently marketed under thetrademark Magic Marker and is especially effective in e making marks onblackboards.

In use, obviously, the device is placed in the clearer chalk tray andmoved therealong on its Wheeled base, the marker engaging theblackboard.

To adjust with great facility the vertical height of bridge 32 withrespect to base 12, the side members 14 and 16 are graduated at regular,preferably one-half inch, intervals. Side members 14 and 16 are notchedtransversely, as at 76, at these intervals as is shown in Fig. 4. Tocomplete the height adjusting means, the inside surface of the elongatedmember 34 is formed with a V-shaped projection 78 at either end adaptedto 3 cooperate selectively with any one of the notches. Thus, to setbridge'32 at the proper height with respect to the base is no problem atall.. The elongated members 34 and 36 are spread away from each otherand the bridge is slid up or down toltheapproximate h'eightdesird. Atthis height the members 34 and136are released and the compression springSSbiases themtoward each other causing the projection 78 to move intothe desired notch, firmly centering the bridge at the exact height. 7

Aside from this effective yet simple means for adjusting the height ofthe bridge'member, my invention provides in a blackboard ruling evicemeans for using conventional writing instrument s, said means includinganti-friction device adapted to space'the frame appropriately from thewriting surface. Thus, no matter how much force is exerted by the useragainst the frame, the intensity of the mark 'made by the marking deviceremains constant. The anti-friction spacing device assures this.

My invention is of special value to teachers of primary school agechildren. In teaching such young children it is often necessary to drawlines of horizontal disposition on a blackboard. In this connection itshould be understood that my device may be used with a plurality ofbridge members and marking instruments so that, for instance, fiveparallel lines could be drawn on a blackboard to symbolize the musicalstaff. This, however, is only one of the many uses of my invention.

It can be seen that my invention combines with a rugged durablestructure a desirable simplicity which means economy in manufacture. Myinvention features means for drawing a line parallel to a supportingsurface utilizing a conventional marking instrument and provides meansfor accurately and simply adjusting the vertical height of theinstrument.

While this invention has been shown in but one form, it is obvious tothose skilled in the art that it is not so limited but is susceptible ofvarious changes and modifications without departing from the scope andspirit of the claimed invention.

I claim:

1. A ruling device, adapted to make lines on a writing surface, saiddevice comprising a rectangular frame having a horizontal base withparallel vertically disposed side members attached to and extendingupward from either end thereof, the upper ends of said side membersbeing attached to the. opposite ends of a top member, said base havingantifriction base rollers attached thereto, said rollers being adaptedtosupport said frame, a

horizontally disposed bridge member attached to and extending betweensaid side members, said bridge member having at least one anti-frictionroller adapted to rollingly engage such writing surface and to keep saidbridge member in spaced relation from such writing surface and saidbridge member comprising a 'pair of elongated members disposed inparallel relation on opposite faces of said framerespectively,'releasable compression means connecting said elongatedmembers and clamping said side members therebetween, said bridge memberhaving mounted thereon between said side members clamping means adaptedto hold in compressive engagement a writing instrument in a positionwhereby said instrument is adapted to write on such writing surface andwhereby said frame may be supported with said base rollers on asupporting surface substantially perpendicular to such writing surfaceand be moved therealong with said bridge rollers and said writinginstrument engagingthe writing surface and making thereon a lineparallel to such supporting surface.

If 2. A ruling device as in claim 1 wherein said compression meansincludes a compression spring biasing said elongated members toward eachother.

3. A ruling device as described in claim 2 wherein said side memberseach'have transverse notches therein at spaced intervals therealong on aface thereof abutted by asurface of one of said elongated members andsaid last mentioned elongated member has fixed projections thereononsaid abuttingsurface at the area of said abutment whereby. saidprojections are adapted to selectively nest in said notches and be heldin said nesting engagement by the compressive. force of said spring;

7 whereby the vertical height of said bridge may be adjusted byspringing said elongated members outwardly against the force of saidspring to a position whereat said projections and notches do .notnestihgly engage, and moving said bridge up or down. 1

7 References Cited in the file of this patent UNITED STATES PATENTS Howell et a1. Dec. 1, 1953

